Combined router/host client allows for ad hoc mobile network

Georgia Tech's computer-science researchers have come up with an innovative wireless system called LifeNet, which, because it combines the host client and router function in the LifeNet-enabled mobile device, can allow for setup of a mobile ad-hoc network that could help in emergency response or in places with little network infrastructure.

Georgia Tech's computer-science researchers have come up with an innovative wireless system called LifeNet, which, because it combines the host client and router function in the LifeNet-enabled mobile device, can allow for setup of a mobile ad-hoc network that could help in emergency response or in places with little network infrastructure.

"Our motivation for developing this is broadband connection to share in a disaster-relief situation," says Santosh Vempala, Georgia Tech computer science professor, who with university grad students Ashwin Paranjpe and Hrushikesh Mehendale worked on developing the LifeNet "Flexible Routing" protocol. The protocol is getting a workout in a campus research project that uses it on Wi-Fi-enabled, portable laptops to set up an instant ad-hoc mobile network for data-sharing among LifeNet-enabled devices.

Each LifeNet-enabled-computer acts as both a host client and a router, able to directly route data to and from any other available LifeNet wireless device, Vempala says, and "if any device has Internet connectivity, they all have it."

While the idea sounds simple, there are significant challenges in developing any kind of blended client/router technology for wireless because devices are constantly getting turned on and off and moved around.

"The paths are changing rapidly," Vempala points out, noting each device has to have a way to know what others on the LifeNet-enabled network are doing and what amount of data can actually get through.

Vempala, who started work on the Flexible Routing protocol about three years ago, says it's open source and available for public use by downloading the software at www.mymanet.org, (which stands for My Mobile Ad-Hoc Network) where version 2.3 is available and 3.0 is expected to be posted next month. Vempala said he welcomes feedback from anyone else trialing it.

The Flexible Routing software is Linux-based but could be ported to other platforms. It's not strictly based on the Internet Protocol standard, such as IPv4 or IPv6, but "is sitting in between the network and data-link layer," Vempala says. "It's something like a Layer 2.5 stack."

The main thing is that the Flexible Routing protocol has to work with existing drivers and applications in use today because the idea is for it to find real-world use, he says.

In the Georgia Tech research project, about 20 students are carrying around laptops that have the LifeNet software on it, plus small hardware USB-type "little routers plugged in from brand names Fonera and Meraki," Vempala says. The students are testing LifeNet to see how well it does data-sharing, including music downloads. The U.S. Federal Aviation Administration also has made a visit to take a look at it.

Each LifeNet-enabled computer maintains a "virtual map of the network and signal space," Vempala says, with the protocol automatically controlling the re-transmission across other LifeNet devices. He acknowledges that the current design of LifeNet could raise questions about security and privacy since so much data is shared across devices, but he says use of encryption may address some concerns.

Around June, the College of Computing researchers intend to start building specialty applications to run on LifeNet. The project has also received a $45,000 in Sustainable Vision Grant funding from the National Collegiate Inventors and Innovators Alliance to move the technology out of the classroom and into the marketplace, Georgia Tech says.